This application claims the priority benefit under 35 U.S.C. §119 of U.S. Provisional Patent Application No. 61/017,951 filed on Dec. 31, 2007, which is hereby incorporated in its entirety by reference.
1. Field
The presently disclosed subject matter relates to a labyrinth box structure that can prevent unwanted substance(s) from intruding into a hose or conduit, in particular, a port leading to a pressure sensor for a vehicle fuel system, breathers for differentials, etc.
2. Description of the Related Art
Existing vehicle fuel systems can employ a tank pressure sensor to monitor the vapor pressure in the fuel tank. Typically, the tank pressure sensor is exposed to the atmosphere via a port to provide the sensor with a pressure reference. The vehicle may pass through debris and fluid that can enter the port and adversely affect the pressure sensor. Conventionally, small joints or complex box arrangements are employed to protect the port leading to the tank pressure sensor from unwanted debris and fluid. Typically, these small joints or boxes are mounted underneath the body of the vehicle, where exposure to unwanted debris and fluid can be excessive.
One example of a conventional small joint arrangement is illustrated in FIGS. 5A and B. This small joint arrangement can include a joint that has a ninety degree bend with the opening pointing down toward the surface upon which the vehicle is travelling. The joint can be made of plastic and mates into a stay or a frame member.
FIGS. 6A-C illustrate a conventional complex box arrangement. Typically, this design is mounted under the floor of the vehicle and can protect the port that is in fluid communication with the tank pressure sensor from water splashed up by the vehicle.
When driving along paved roads, either of these conventional arrangements offer sufficient protection to the tank pressure sensor from unwanted debris and fluids. However, because these structures are usually mounted underneath the vehicle body, they may not provide sufficient protection to the tank pressure sensor from unwanted debris and fluid when driving off-road and/or through deep water and/or snow, etc.